| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Renesas R-Car Gen2 DMA Controller Driver |
| * |
| * Copyright (C) 2014 Renesas Electronics Inc. |
| * |
| * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com> |
| */ |
| |
| #include <linux/delay.h> |
| #include <linux/dma-mapping.h> |
| #include <linux/dmaengine.h> |
| #include <linux/interrupt.h> |
| #include <linux/list.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/of_dma.h> |
| #include <linux/of_platform.h> |
| #include <linux/platform_device.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| |
| #include "../dmaengine.h" |
| |
| /* |
| * struct rcar_dmac_xfer_chunk - Descriptor for a hardware transfer |
| * @node: entry in the parent's chunks list |
| * @src_addr: device source address |
| * @dst_addr: device destination address |
| * @size: transfer size in bytes |
| */ |
| struct rcar_dmac_xfer_chunk { |
| struct list_head node; |
| |
| dma_addr_t src_addr; |
| dma_addr_t dst_addr; |
| u32 size; |
| }; |
| |
| /* |
| * struct rcar_dmac_hw_desc - Hardware descriptor for a transfer chunk |
| * @sar: value of the SAR register (source address) |
| * @dar: value of the DAR register (destination address) |
| * @tcr: value of the TCR register (transfer count) |
| */ |
| struct rcar_dmac_hw_desc { |
| u32 sar; |
| u32 dar; |
| u32 tcr; |
| u32 reserved; |
| } __attribute__((__packed__)); |
| |
| /* |
| * struct rcar_dmac_desc - R-Car Gen2 DMA Transfer Descriptor |
| * @async_tx: base DMA asynchronous transaction descriptor |
| * @direction: direction of the DMA transfer |
| * @xfer_shift: log2 of the transfer size |
| * @chcr: value of the channel configuration register for this transfer |
| * @node: entry in the channel's descriptors lists |
| * @chunks: list of transfer chunks for this transfer |
| * @running: the transfer chunk being currently processed |
| * @nchunks: number of transfer chunks for this transfer |
| * @hwdescs.use: whether the transfer descriptor uses hardware descriptors |
| * @hwdescs.mem: hardware descriptors memory for the transfer |
| * @hwdescs.dma: device address of the hardware descriptors memory |
| * @hwdescs.size: size of the hardware descriptors in bytes |
| * @size: transfer size in bytes |
| * @cyclic: when set indicates that the DMA transfer is cyclic |
| */ |
| struct rcar_dmac_desc { |
| struct dma_async_tx_descriptor async_tx; |
| enum dma_transfer_direction direction; |
| unsigned int xfer_shift; |
| u32 chcr; |
| |
| struct list_head node; |
| struct list_head chunks; |
| struct rcar_dmac_xfer_chunk *running; |
| unsigned int nchunks; |
| |
| struct { |
| bool use; |
| struct rcar_dmac_hw_desc *mem; |
| dma_addr_t dma; |
| size_t size; |
| } hwdescs; |
| |
| unsigned int size; |
| bool cyclic; |
| }; |
| |
| #define to_rcar_dmac_desc(d) container_of(d, struct rcar_dmac_desc, async_tx) |
| |
| /* |
| * struct rcar_dmac_desc_page - One page worth of descriptors |
| * @node: entry in the channel's pages list |
| * @descs: array of DMA descriptors |
| * @chunks: array of transfer chunk descriptors |
| */ |
| struct rcar_dmac_desc_page { |
| struct list_head node; |
| |
| union { |
| struct rcar_dmac_desc descs[0]; |
| struct rcar_dmac_xfer_chunk chunks[0]; |
| }; |
| }; |
| |
| #define RCAR_DMAC_DESCS_PER_PAGE \ |
| ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, descs)) / \ |
| sizeof(struct rcar_dmac_desc)) |
| #define RCAR_DMAC_XFER_CHUNKS_PER_PAGE \ |
| ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, chunks)) / \ |
| sizeof(struct rcar_dmac_xfer_chunk)) |
| |
| /* |
| * struct rcar_dmac_chan_slave - Slave configuration |
| * @slave_addr: slave memory address |
| * @xfer_size: size (in bytes) of hardware transfers |
| */ |
| struct rcar_dmac_chan_slave { |
| phys_addr_t slave_addr; |
| unsigned int xfer_size; |
| }; |
| |
| /* |
| * struct rcar_dmac_chan_map - Map of slave device phys to dma address |
| * @addr: slave dma address |
| * @dir: direction of mapping |
| * @slave: slave configuration that is mapped |
| */ |
| struct rcar_dmac_chan_map { |
| dma_addr_t addr; |
| enum dma_data_direction dir; |
| struct rcar_dmac_chan_slave slave; |
| }; |
| |
| /* |
| * struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel |
| * @chan: base DMA channel object |
| * @iomem: channel I/O memory base |
| * @index: index of this channel in the controller |
| * @irq: channel IRQ |
| * @src: slave memory address and size on the source side |
| * @dst: slave memory address and size on the destination side |
| * @mid_rid: hardware MID/RID for the DMA client using this channel |
| * @lock: protects the channel CHCR register and the desc members |
| * @desc.free: list of free descriptors |
| * @desc.pending: list of pending descriptors (submitted with tx_submit) |
| * @desc.active: list of active descriptors (activated with issue_pending) |
| * @desc.done: list of completed descriptors |
| * @desc.wait: list of descriptors waiting for an ack |
| * @desc.running: the descriptor being processed (a member of the active list) |
| * @desc.chunks_free: list of free transfer chunk descriptors |
| * @desc.pages: list of pages used by allocated descriptors |
| */ |
| struct rcar_dmac_chan { |
| struct dma_chan chan; |
| void __iomem *iomem; |
| unsigned int index; |
| int irq; |
| |
| struct rcar_dmac_chan_slave src; |
| struct rcar_dmac_chan_slave dst; |
| struct rcar_dmac_chan_map map; |
| int mid_rid; |
| |
| spinlock_t lock; |
| |
| struct { |
| struct list_head free; |
| struct list_head pending; |
| struct list_head active; |
| struct list_head done; |
| struct list_head wait; |
| struct rcar_dmac_desc *running; |
| |
| struct list_head chunks_free; |
| |
| struct list_head pages; |
| } desc; |
| }; |
| |
| #define to_rcar_dmac_chan(c) container_of(c, struct rcar_dmac_chan, chan) |
| |
| /* |
| * struct rcar_dmac - R-Car Gen2 DMA Controller |
| * @engine: base DMA engine object |
| * @dev: the hardware device |
| * @iomem: remapped I/O memory base |
| * @n_channels: number of available channels |
| * @channels: array of DMAC channels |
| * @modules: bitmask of client modules in use |
| */ |
| struct rcar_dmac { |
| struct dma_device engine; |
| struct device *dev; |
| void __iomem *iomem; |
| |
| unsigned int n_channels; |
| struct rcar_dmac_chan *channels; |
| |
| DECLARE_BITMAP(modules, 256); |
| }; |
| |
| #define to_rcar_dmac(d) container_of(d, struct rcar_dmac, engine) |
| |
| /* ----------------------------------------------------------------------------- |
| * Registers |
| */ |
| |
| #define RCAR_DMAC_CHAN_OFFSET(i) (0x8000 + 0x80 * (i)) |
| |
| #define RCAR_DMAISTA 0x0020 |
| #define RCAR_DMASEC 0x0030 |
| #define RCAR_DMAOR 0x0060 |
| #define RCAR_DMAOR_PRI_FIXED (0 << 8) |
| #define RCAR_DMAOR_PRI_ROUND_ROBIN (3 << 8) |
| #define RCAR_DMAOR_AE (1 << 2) |
| #define RCAR_DMAOR_DME (1 << 0) |
| #define RCAR_DMACHCLR 0x0080 |
| #define RCAR_DMADPSEC 0x00a0 |
| |
| #define RCAR_DMASAR 0x0000 |
| #define RCAR_DMADAR 0x0004 |
| #define RCAR_DMATCR 0x0008 |
| #define RCAR_DMATCR_MASK 0x00ffffff |
| #define RCAR_DMATSR 0x0028 |
| #define RCAR_DMACHCR 0x000c |
| #define RCAR_DMACHCR_CAE (1 << 31) |
| #define RCAR_DMACHCR_CAIE (1 << 30) |
| #define RCAR_DMACHCR_DPM_DISABLED (0 << 28) |
| #define RCAR_DMACHCR_DPM_ENABLED (1 << 28) |
| #define RCAR_DMACHCR_DPM_REPEAT (2 << 28) |
| #define RCAR_DMACHCR_DPM_INFINITE (3 << 28) |
| #define RCAR_DMACHCR_RPT_SAR (1 << 27) |
| #define RCAR_DMACHCR_RPT_DAR (1 << 26) |
| #define RCAR_DMACHCR_RPT_TCR (1 << 25) |
| #define RCAR_DMACHCR_DPB (1 << 22) |
| #define RCAR_DMACHCR_DSE (1 << 19) |
| #define RCAR_DMACHCR_DSIE (1 << 18) |
| #define RCAR_DMACHCR_TS_1B ((0 << 20) | (0 << 3)) |
| #define RCAR_DMACHCR_TS_2B ((0 << 20) | (1 << 3)) |
| #define RCAR_DMACHCR_TS_4B ((0 << 20) | (2 << 3)) |
| #define RCAR_DMACHCR_TS_16B ((0 << 20) | (3 << 3)) |
| #define RCAR_DMACHCR_TS_32B ((1 << 20) | (0 << 3)) |
| #define RCAR_DMACHCR_TS_64B ((1 << 20) | (1 << 3)) |
| #define RCAR_DMACHCR_TS_8B ((1 << 20) | (3 << 3)) |
| #define RCAR_DMACHCR_DM_FIXED (0 << 14) |
| #define RCAR_DMACHCR_DM_INC (1 << 14) |
| #define RCAR_DMACHCR_DM_DEC (2 << 14) |
| #define RCAR_DMACHCR_SM_FIXED (0 << 12) |
| #define RCAR_DMACHCR_SM_INC (1 << 12) |
| #define RCAR_DMACHCR_SM_DEC (2 << 12) |
| #define RCAR_DMACHCR_RS_AUTO (4 << 8) |
| #define RCAR_DMACHCR_RS_DMARS (8 << 8) |
| #define RCAR_DMACHCR_IE (1 << 2) |
| #define RCAR_DMACHCR_TE (1 << 1) |
| #define RCAR_DMACHCR_DE (1 << 0) |
| #define RCAR_DMATCRB 0x0018 |
| #define RCAR_DMATSRB 0x0038 |
| #define RCAR_DMACHCRB 0x001c |
| #define RCAR_DMACHCRB_DCNT(n) ((n) << 24) |
| #define RCAR_DMACHCRB_DPTR_MASK (0xff << 16) |
| #define RCAR_DMACHCRB_DPTR_SHIFT 16 |
| #define RCAR_DMACHCRB_DRST (1 << 15) |
| #define RCAR_DMACHCRB_DTS (1 << 8) |
| #define RCAR_DMACHCRB_SLM_NORMAL (0 << 4) |
| #define RCAR_DMACHCRB_SLM_CLK(n) ((8 | (n)) << 4) |
| #define RCAR_DMACHCRB_PRI(n) ((n) << 0) |
| #define RCAR_DMARS 0x0040 |
| #define RCAR_DMABUFCR 0x0048 |
| #define RCAR_DMABUFCR_MBU(n) ((n) << 16) |
| #define RCAR_DMABUFCR_ULB(n) ((n) << 0) |
| #define RCAR_DMADPBASE 0x0050 |
| #define RCAR_DMADPBASE_MASK 0xfffffff0 |
| #define RCAR_DMADPBASE_SEL (1 << 0) |
| #define RCAR_DMADPCR 0x0054 |
| #define RCAR_DMADPCR_DIPT(n) ((n) << 24) |
| #define RCAR_DMAFIXSAR 0x0010 |
| #define RCAR_DMAFIXDAR 0x0014 |
| #define RCAR_DMAFIXDPBASE 0x0060 |
| |
| /* Hardcode the MEMCPY transfer size to 4 bytes. */ |
| #define RCAR_DMAC_MEMCPY_XFER_SIZE 4 |
| |
| /* ----------------------------------------------------------------------------- |
| * Device access |
| */ |
| |
| static void rcar_dmac_write(struct rcar_dmac *dmac, u32 reg, u32 data) |
| { |
| if (reg == RCAR_DMAOR) |
| writew(data, dmac->iomem + reg); |
| else |
| writel(data, dmac->iomem + reg); |
| } |
| |
| static u32 rcar_dmac_read(struct rcar_dmac *dmac, u32 reg) |
| { |
| if (reg == RCAR_DMAOR) |
| return readw(dmac->iomem + reg); |
| else |
| return readl(dmac->iomem + reg); |
| } |
| |
| static u32 rcar_dmac_chan_read(struct rcar_dmac_chan *chan, u32 reg) |
| { |
| if (reg == RCAR_DMARS) |
| return readw(chan->iomem + reg); |
| else |
| return readl(chan->iomem + reg); |
| } |
| |
| static void rcar_dmac_chan_write(struct rcar_dmac_chan *chan, u32 reg, u32 data) |
| { |
| if (reg == RCAR_DMARS) |
| writew(data, chan->iomem + reg); |
| else |
| writel(data, chan->iomem + reg); |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * Initialization and configuration |
| */ |
| |
| static bool rcar_dmac_chan_is_busy(struct rcar_dmac_chan *chan) |
| { |
| u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); |
| |
| return !!(chcr & (RCAR_DMACHCR_DE | RCAR_DMACHCR_TE)); |
| } |
| |
| static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan) |
| { |
| struct rcar_dmac_desc *desc = chan->desc.running; |
| u32 chcr = desc->chcr; |
| |
| WARN_ON_ONCE(rcar_dmac_chan_is_busy(chan)); |
| |
| if (chan->mid_rid >= 0) |
| rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid); |
| |
| if (desc->hwdescs.use) { |
| struct rcar_dmac_xfer_chunk *chunk = |
| list_first_entry(&desc->chunks, |
| struct rcar_dmac_xfer_chunk, node); |
| |
| dev_dbg(chan->chan.device->dev, |
| "chan%u: queue desc %p: %u@%pad\n", |
| chan->index, desc, desc->nchunks, &desc->hwdescs.dma); |
| |
| #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT |
| rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR, |
| chunk->src_addr >> 32); |
| rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR, |
| chunk->dst_addr >> 32); |
| rcar_dmac_chan_write(chan, RCAR_DMAFIXDPBASE, |
| desc->hwdescs.dma >> 32); |
| #endif |
| rcar_dmac_chan_write(chan, RCAR_DMADPBASE, |
| (desc->hwdescs.dma & 0xfffffff0) | |
| RCAR_DMADPBASE_SEL); |
| rcar_dmac_chan_write(chan, RCAR_DMACHCRB, |
| RCAR_DMACHCRB_DCNT(desc->nchunks - 1) | |
| RCAR_DMACHCRB_DRST); |
| |
| /* |
| * Errata: When descriptor memory is accessed through an IOMMU |
| * the DMADAR register isn't initialized automatically from the |
| * first descriptor at beginning of transfer by the DMAC like it |
| * should. Initialize it manually with the destination address |
| * of the first chunk. |
| */ |
| rcar_dmac_chan_write(chan, RCAR_DMADAR, |
| chunk->dst_addr & 0xffffffff); |
| |
| /* |
| * Program the descriptor stage interrupt to occur after the end |
| * of the first stage. |
| */ |
| rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(1)); |
| |
| chcr |= RCAR_DMACHCR_RPT_SAR | RCAR_DMACHCR_RPT_DAR |
| | RCAR_DMACHCR_RPT_TCR | RCAR_DMACHCR_DPB; |
| |
| /* |
| * If the descriptor isn't cyclic enable normal descriptor mode |
| * and the transfer completion interrupt. |
| */ |
| if (!desc->cyclic) |
| chcr |= RCAR_DMACHCR_DPM_ENABLED | RCAR_DMACHCR_IE; |
| /* |
| * If the descriptor is cyclic and has a callback enable the |
| * descriptor stage interrupt in infinite repeat mode. |
| */ |
| else if (desc->async_tx.callback) |
| chcr |= RCAR_DMACHCR_DPM_INFINITE | RCAR_DMACHCR_DSIE; |
| /* |
| * Otherwise just select infinite repeat mode without any |
| * interrupt. |
| */ |
| else |
| chcr |= RCAR_DMACHCR_DPM_INFINITE; |
| } else { |
| struct rcar_dmac_xfer_chunk *chunk = desc->running; |
| |
| dev_dbg(chan->chan.device->dev, |
| "chan%u: queue chunk %p: %u@%pad -> %pad\n", |
| chan->index, chunk, chunk->size, &chunk->src_addr, |
| &chunk->dst_addr); |
| |
| #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT |
| rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR, |
| chunk->src_addr >> 32); |
| rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR, |
| chunk->dst_addr >> 32); |
| #endif |
| rcar_dmac_chan_write(chan, RCAR_DMASAR, |
| chunk->src_addr & 0xffffffff); |
| rcar_dmac_chan_write(chan, RCAR_DMADAR, |
| chunk->dst_addr & 0xffffffff); |
| rcar_dmac_chan_write(chan, RCAR_DMATCR, |
| chunk->size >> desc->xfer_shift); |
| |
| chcr |= RCAR_DMACHCR_DPM_DISABLED | RCAR_DMACHCR_IE; |
| } |
| |
| rcar_dmac_chan_write(chan, RCAR_DMACHCR, |
| chcr | RCAR_DMACHCR_DE | RCAR_DMACHCR_CAIE); |
| } |
| |
| static int rcar_dmac_init(struct rcar_dmac *dmac) |
| { |
| u16 dmaor; |
| |
| /* Clear all channels and enable the DMAC globally. */ |
| rcar_dmac_write(dmac, RCAR_DMACHCLR, GENMASK(dmac->n_channels - 1, 0)); |
| rcar_dmac_write(dmac, RCAR_DMAOR, |
| RCAR_DMAOR_PRI_FIXED | RCAR_DMAOR_DME); |
| |
| dmaor = rcar_dmac_read(dmac, RCAR_DMAOR); |
| if ((dmaor & (RCAR_DMAOR_AE | RCAR_DMAOR_DME)) != RCAR_DMAOR_DME) { |
| dev_warn(dmac->dev, "DMAOR initialization failed.\n"); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * Descriptors submission |
| */ |
| |
| static dma_cookie_t rcar_dmac_tx_submit(struct dma_async_tx_descriptor *tx) |
| { |
| struct rcar_dmac_chan *chan = to_rcar_dmac_chan(tx->chan); |
| struct rcar_dmac_desc *desc = to_rcar_dmac_desc(tx); |
| unsigned long flags; |
| dma_cookie_t cookie; |
| |
| spin_lock_irqsave(&chan->lock, flags); |
| |
| cookie = dma_cookie_assign(tx); |
| |
| dev_dbg(chan->chan.device->dev, "chan%u: submit #%d@%p\n", |
| chan->index, tx->cookie, desc); |
| |
| list_add_tail(&desc->node, &chan->desc.pending); |
| desc->running = list_first_entry(&desc->chunks, |
| struct rcar_dmac_xfer_chunk, node); |
| |
| spin_unlock_irqrestore(&chan->lock, flags); |
| |
| return cookie; |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * Descriptors allocation and free |
| */ |
| |
| /* |
| * rcar_dmac_desc_alloc - Allocate a page worth of DMA descriptors |
| * @chan: the DMA channel |
| * @gfp: allocation flags |
| */ |
| static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) |
| { |
| struct rcar_dmac_desc_page *page; |
| unsigned long flags; |
| LIST_HEAD(list); |
| unsigned int i; |
| |
| page = (void *)get_zeroed_page(gfp); |
| if (!page) |
| return -ENOMEM; |
| |
| for (i = 0; i < RCAR_DMAC_DESCS_PER_PAGE; ++i) { |
| struct rcar_dmac_desc *desc = &page->descs[i]; |
| |
| dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan); |
| desc->async_tx.tx_submit = rcar_dmac_tx_submit; |
| INIT_LIST_HEAD(&desc->chunks); |
| |
| list_add_tail(&desc->node, &list); |
| } |
| |
| spin_lock_irqsave(&chan->lock, flags); |
| list_splice_tail(&list, &chan->desc.free); |
| list_add_tail(&page->node, &chan->desc.pages); |
| spin_unlock_irqrestore(&chan->lock, flags); |
| |
| return 0; |
| } |
| |
| /* |
| * rcar_dmac_desc_put - Release a DMA transfer descriptor |
| * @chan: the DMA channel |
| * @desc: the descriptor |
| * |
| * Put the descriptor and its transfer chunk descriptors back in the channel's |
| * free descriptors lists. The descriptor's chunks list will be reinitialized to |
| * an empty list as a result. |
| * |
| * The descriptor must have been removed from the channel's lists before calling |
| * this function. |
| */ |
| static void rcar_dmac_desc_put(struct rcar_dmac_chan *chan, |
| struct rcar_dmac_desc *desc) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&chan->lock, flags); |
| list_splice_tail_init(&desc->chunks, &chan->desc.chunks_free); |
| list_add(&desc->node, &chan->desc.free); |
| spin_unlock_irqrestore(&chan->lock, flags); |
| } |
| |
| static void rcar_dmac_desc_recycle_acked(struct rcar_dmac_chan *chan) |
| { |
| struct rcar_dmac_desc *desc, *_desc; |
| unsigned long flags; |
| LIST_HEAD(list); |
| |
| /* |
| * We have to temporarily move all descriptors from the wait list to a |
| * local list as iterating over the wait list, even with |
| * list_for_each_entry_safe, isn't safe if we release the channel lock |
| * around the rcar_dmac_desc_put() call. |
| */ |
| spin_lock_irqsave(&chan->lock, flags); |
| list_splice_init(&chan->desc.wait, &list); |
| spin_unlock_irqrestore(&chan->lock, flags); |
| |
| list_for_each_entry_safe(desc, _desc, &list, node) { |
| if (async_tx_test_ack(&desc->async_tx)) { |
| list_del(&desc->node); |
| rcar_dmac_desc_put(chan, desc); |
| } |
| } |
| |
| if (list_empty(&list)) |
| return; |
| |
| /* Put the remaining descriptors back in the wait list. */ |
| spin_lock_irqsave(&chan->lock, flags); |
| list_splice(&list, &chan->desc.wait); |
| spin_unlock_irqrestore(&chan->lock, flags); |
| } |
| |
| /* |
| * rcar_dmac_desc_get - Allocate a descriptor for a DMA transfer |
| * @chan: the DMA channel |
| * |
| * Locking: This function must be called in a non-atomic context. |
| * |
| * Return: A pointer to the allocated descriptor or NULL if no descriptor can |
| * be allocated. |
| */ |
| static struct rcar_dmac_desc *rcar_dmac_desc_get(struct rcar_dmac_chan *chan) |
| { |
| struct rcar_dmac_desc *desc; |
| unsigned long flags; |
| int ret; |
| |
| /* Recycle acked descriptors before attempting allocation. */ |
| rcar_dmac_desc_recycle_acked(chan); |
| |
| spin_lock_irqsave(&chan->lock, flags); |
| |
| while (list_empty(&chan->desc.free)) { |
| /* |
| * No free descriptors, allocate a page worth of them and try |
| * again, as someone else could race us to get the newly |
| * allocated descriptors. If the allocation fails return an |
| * error. |
| */ |
| spin_unlock_irqrestore(&chan->lock, flags); |
| ret = rcar_dmac_desc_alloc(chan, GFP_NOWAIT); |
| if (ret < 0) |
| return NULL; |
| spin_lock_irqsave(&chan->lock, flags); |
| } |
| |
| desc = list_first_entry(&chan->desc.free, struct rcar_dmac_desc, node); |
| list_del(&desc->node); |
| |
| spin_unlock_irqrestore(&chan->lock, flags); |
| |
| return desc; |
| } |
| |
| /* |
| * rcar_dmac_xfer_chunk_alloc - Allocate a page worth of transfer chunks |
| * @chan: the DMA channel |
| * @gfp: allocation flags |
| */ |
| static int rcar_dmac_xfer_chunk_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) |
| { |
| struct rcar_dmac_desc_page *page; |
| unsigned long flags; |
| LIST_HEAD(list); |
| unsigned int i; |
| |
| page = (void *)get_zeroed_page(gfp); |
| if (!page) |
| return -ENOMEM; |
| |
| for (i = 0; i < RCAR_DMAC_XFER_CHUNKS_PER_PAGE; ++i) { |
| struct rcar_dmac_xfer_chunk *chunk = &page->chunks[i]; |
| |
| list_add_tail(&chunk->node, &list); |
| } |
| |
| spin_lock_irqsave(&chan->lock, flags); |
| list_splice_tail(&list, &chan->desc.chunks_free); |
| list_add_tail(&page->node, &chan->desc.pages); |
| spin_unlock_irqrestore(&chan->lock, flags); |
| |
| return 0; |
| } |
| |
| /* |
| * rcar_dmac_xfer_chunk_get - Allocate a transfer chunk for a DMA transfer |
| * @chan: the DMA channel |
| * |
| * Locking: This function must be called in a non-atomic context. |
| * |
| * Return: A pointer to the allocated transfer chunk descriptor or NULL if no |
| * descriptor can be allocated. |
| */ |
| static struct rcar_dmac_xfer_chunk * |
| rcar_dmac_xfer_chunk_get(struct rcar_dmac_chan *chan) |
| { |
| struct rcar_dmac_xfer_chunk *chunk; |
| unsigned long flags; |
| int ret; |
| |
| spin_lock_irqsave(&chan->lock, flags); |
| |
| while (list_empty(&chan->desc.chunks_free)) { |
| /* |
| * No free descriptors, allocate a page worth of them and try |
| * again, as someone else could race us to get the newly |
| * allocated descriptors. If the allocation fails return an |
| * error. |
| */ |
| spin_unlock_irqrestore(&chan->lock, flags); |
| ret = rcar_dmac_xfer_chunk_alloc(chan, GFP_NOWAIT); |
| if (ret < 0) |
| return NULL; |
| spin_lock_irqsave(&chan->lock, flags); |
| } |
| |
| chunk = list_first_entry(&chan->desc.chunks_free, |
| struct rcar_dmac_xfer_chunk, node); |
| list_del(&chunk->node); |
| |
| spin_unlock_irqrestore(&chan->lock, flags); |
| |
| return chunk; |
| } |
| |
| static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan, |
| struct rcar_dmac_desc *desc, size_t size) |
| { |
| /* |
| * dma_alloc_coherent() allocates memory in page size increments. To |
| * avoid reallocating the hardware descriptors when the allocated size |
| * wouldn't change align the requested size to a multiple of the page |
| * size. |
| */ |
| size = PAGE_ALIGN(size); |
| |
| if (desc->hwdescs.size == size) |
| return; |
| |
| if (desc->hwdescs.mem) { |
| dma_free_coherent(chan->chan.device->dev, desc->hwdescs.size, |
| desc->hwdescs.mem, desc->hwdescs.dma); |
| desc->hwdescs.mem = NULL; |
| desc->hwdescs.size = 0; |
| } |
| |
| if (!size) |
| return; |
| |
| desc->hwdescs.mem = dma_alloc_coherent(chan->chan.device->dev, size, |
| &desc->hwdescs.dma, GFP_NOWAIT); |
| if (!desc->hwdescs.mem) |
| return; |
| |
| desc->hwdescs.size = size; |
| } |
| |
| static int rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan, |
| struct rcar_dmac_desc *desc) |
| { |
| struct rcar_dmac_xfer_chunk *chunk; |
| struct rcar_dmac_hw_desc *hwdesc; |
| |
| rcar_dmac_realloc_hwdesc(chan, desc, desc->nchunks * sizeof(*hwdesc)); |
| |
| hwdesc = desc->hwdescs.mem; |
| if (!hwdesc) |
| return -ENOMEM; |
| |
| list_for_each_entry(chunk, &desc->chunks, node) { |
| hwdesc->sar = chunk->src_addr; |
| hwdesc->dar = chunk->dst_addr; |
| hwdesc->tcr = chunk->size >> desc->xfer_shift; |
| hwdesc++; |
| } |
| |
| return 0; |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * Stop and reset |
| */ |
| static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan) |
| { |
| u32 chcr; |
| unsigned int i; |
| |
| /* |
| * Ensure that the setting of the DE bit is actually 0 after |
| * clearing it. |
| */ |
| for (i = 0; i < 1024; i++) { |
| chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); |
| if (!(chcr & RCAR_DMACHCR_DE)) |
| return; |
| udelay(1); |
| } |
| |
| dev_err(chan->chan.device->dev, "CHCR DE check error\n"); |
| } |
| |
| static void rcar_dmac_clear_chcr_de(struct rcar_dmac_chan *chan) |
| { |
| u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); |
| |
| /* set DE=0 and flush remaining data */ |
| rcar_dmac_chan_write(chan, RCAR_DMACHCR, (chcr & ~RCAR_DMACHCR_DE)); |
| |
| /* make sure all remaining data was flushed */ |
| rcar_dmac_chcr_de_barrier(chan); |
| } |
| |
| static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) |
| { |
| u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); |
| |
| chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE | |
| RCAR_DMACHCR_TE | RCAR_DMACHCR_DE | |
| RCAR_DMACHCR_CAE | RCAR_DMACHCR_CAIE); |
| rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr); |
| rcar_dmac_chcr_de_barrier(chan); |
| } |
| |
| static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan) |
| { |
| struct rcar_dmac_desc *desc, *_desc; |
| unsigned long flags; |
| LIST_HEAD(descs); |
| |
| spin_lock_irqsave(&chan->lock, flags); |
| |
| /* Move all non-free descriptors to the local lists. */ |
| list_splice_init(&chan->desc.pending, &descs); |
| list_splice_init(&chan->desc.active, &descs); |
| list_splice_init(&chan->desc.done, &descs); |
| list_splice_init(&chan->desc.wait, &descs); |
| |
| chan->desc.running = NULL; |
| |
| spin_unlock_irqrestore(&chan->lock, flags); |
| |
| list_for_each_entry_safe(desc, _desc, &descs, node) { |
| list_del(&desc->node); |
| rcar_dmac_desc_put(chan, desc); |
| } |
| } |
| |
| static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac) |
| { |
| unsigned int i; |
| |
| /* Stop all channels. */ |
| for (i = 0; i < dmac->n_channels; ++i) { |
| struct rcar_dmac_chan *chan = &dmac->channels[i]; |
| |
| /* Stop and reinitialize the channel. */ |
| spin_lock_irq(&chan->lock); |
| rcar_dmac_chan_halt(chan); |
| spin_unlock_irq(&chan->lock); |
| } |
| } |
| |
| static int rcar_dmac_chan_pause(struct dma_chan *chan) |
| { |
| unsigned long flags; |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| |
| spin_lock_irqsave(&rchan->lock, flags); |
| rcar_dmac_clear_chcr_de(rchan); |
| spin_unlock_irqrestore(&rchan->lock, flags); |
| |
| return 0; |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * Descriptors preparation |
| */ |
| |
| static int rcar_dmac_chan_configure_desc(struct rcar_dmac_chan *chan, |
| struct rcar_dmac_desc *desc) |
| { |
| static const u32 chcr_ts[] = { |
| RCAR_DMACHCR_TS_1B, RCAR_DMACHCR_TS_2B, |
| RCAR_DMACHCR_TS_4B, RCAR_DMACHCR_TS_8B, |
| RCAR_DMACHCR_TS_16B, RCAR_DMACHCR_TS_32B, |
| RCAR_DMACHCR_TS_64B, |
| }; |
| |
| unsigned int xfer_size; |
| u32 chcr; |
| |
| switch (desc->direction) { |
| case DMA_DEV_TO_MEM: |
| chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_FIXED |
| | RCAR_DMACHCR_RS_DMARS; |
| xfer_size = chan->src.xfer_size; |
| break; |
| |
| case DMA_MEM_TO_DEV: |
| chcr = RCAR_DMACHCR_DM_FIXED | RCAR_DMACHCR_SM_INC |
| | RCAR_DMACHCR_RS_DMARS; |
| xfer_size = chan->dst.xfer_size; |
| break; |
| |
| case DMA_MEM_TO_MEM: |
| default: |
| chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_INC |
| | RCAR_DMACHCR_RS_AUTO; |
| xfer_size = RCAR_DMAC_MEMCPY_XFER_SIZE; |
| break; |
| } |
| |
| if (xfer_size > 0x40) /* bus width */ |
| return -EINVAL; |
| |
| desc->xfer_shift = ilog2(xfer_size); |
| desc->chcr = chcr | chcr_ts[desc->xfer_shift]; |
| |
| return 0; |
| } |
| |
| /* |
| * rcar_dmac_chan_prep_sg - prepare transfer descriptors from an SG list |
| * |
| * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also |
| * converted to scatter-gather to guarantee consistent locking and a correct |
| * list manipulation. For slave DMA direction carries the usual meaning, and, |
| * logically, the SG list is RAM and the addr variable contains slave address, |
| * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM |
| * and the SG list contains only one element and points at the source buffer. |
| */ |
| static struct dma_async_tx_descriptor * |
| rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl, |
| unsigned int sg_len, dma_addr_t dev_addr, |
| enum dma_transfer_direction dir, unsigned long dma_flags, |
| bool cyclic) |
| { |
| struct rcar_dmac_xfer_chunk *chunk; |
| struct rcar_dmac_desc *desc; |
| struct scatterlist *sg; |
| unsigned int nchunks = 0; |
| unsigned int max_chunk_size; |
| unsigned int full_size = 0; |
| bool cross_boundary = false; |
| unsigned int i; |
| int ret; |
| #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT |
| u32 high_dev_addr; |
| u32 high_mem_addr; |
| #endif |
| |
| desc = rcar_dmac_desc_get(chan); |
| if (!desc) |
| return NULL; |
| |
| desc->async_tx.flags = dma_flags; |
| desc->async_tx.cookie = -EBUSY; |
| |
| desc->cyclic = cyclic; |
| desc->direction = dir; |
| |
| ret = rcar_dmac_chan_configure_desc(chan, desc); |
| if (ret) { |
| rcar_dmac_desc_put(chan, desc); |
| return NULL; |
| } |
| |
| max_chunk_size = RCAR_DMATCR_MASK << desc->xfer_shift; |
| |
| /* |
| * Allocate and fill the transfer chunk descriptors. We own the only |
| * reference to the DMA descriptor, there's no need for locking. |
| */ |
| for_each_sg(sgl, sg, sg_len, i) { |
| dma_addr_t mem_addr = sg_dma_address(sg); |
| unsigned int len = sg_dma_len(sg); |
| |
| full_size += len; |
| |
| #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT |
| if (i == 0) { |
| high_dev_addr = dev_addr >> 32; |
| high_mem_addr = mem_addr >> 32; |
| } |
| |
| if ((dev_addr >> 32 != high_dev_addr) || |
| (mem_addr >> 32 != high_mem_addr)) |
| cross_boundary = true; |
| #endif |
| while (len) { |
| unsigned int size = min(len, max_chunk_size); |
| |
| #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT |
| /* |
| * Prevent individual transfers from crossing 4GB |
| * boundaries. |
| */ |
| if (dev_addr >> 32 != (dev_addr + size - 1) >> 32) { |
| size = ALIGN(dev_addr, 1ULL << 32) - dev_addr; |
| cross_boundary = true; |
| } |
| if (mem_addr >> 32 != (mem_addr + size - 1) >> 32) { |
| size = ALIGN(mem_addr, 1ULL << 32) - mem_addr; |
| cross_boundary = true; |
| } |
| #endif |
| |
| chunk = rcar_dmac_xfer_chunk_get(chan); |
| if (!chunk) { |
| rcar_dmac_desc_put(chan, desc); |
| return NULL; |
| } |
| |
| if (dir == DMA_DEV_TO_MEM) { |
| chunk->src_addr = dev_addr; |
| chunk->dst_addr = mem_addr; |
| } else { |
| chunk->src_addr = mem_addr; |
| chunk->dst_addr = dev_addr; |
| } |
| |
| chunk->size = size; |
| |
| dev_dbg(chan->chan.device->dev, |
| "chan%u: chunk %p/%p sgl %u@%p, %u/%u %pad -> %pad\n", |
| chan->index, chunk, desc, i, sg, size, len, |
| &chunk->src_addr, &chunk->dst_addr); |
| |
| mem_addr += size; |
| if (dir == DMA_MEM_TO_MEM) |
| dev_addr += size; |
| |
| len -= size; |
| |
| list_add_tail(&chunk->node, &desc->chunks); |
| nchunks++; |
| } |
| } |
| |
| desc->nchunks = nchunks; |
| desc->size = full_size; |
| |
| /* |
| * Use hardware descriptor lists if possible when more than one chunk |
| * needs to be transferred (otherwise they don't make much sense). |
| * |
| * Source/Destination address should be located in same 4GiB region |
| * in the 40bit address space when it uses Hardware descriptor, |
| * and cross_boundary is checking it. |
| */ |
| desc->hwdescs.use = !cross_boundary && nchunks > 1; |
| if (desc->hwdescs.use) { |
| if (rcar_dmac_fill_hwdesc(chan, desc) < 0) |
| desc->hwdescs.use = false; |
| } |
| |
| return &desc->async_tx; |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * DMA engine operations |
| */ |
| |
| static int rcar_dmac_alloc_chan_resources(struct dma_chan *chan) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| int ret; |
| |
| INIT_LIST_HEAD(&rchan->desc.chunks_free); |
| INIT_LIST_HEAD(&rchan->desc.pages); |
| |
| /* Preallocate descriptors. */ |
| ret = rcar_dmac_xfer_chunk_alloc(rchan, GFP_KERNEL); |
| if (ret < 0) |
| return -ENOMEM; |
| |
| ret = rcar_dmac_desc_alloc(rchan, GFP_KERNEL); |
| if (ret < 0) |
| return -ENOMEM; |
| |
| return pm_runtime_get_sync(chan->device->dev); |
| } |
| |
| static void rcar_dmac_free_chan_resources(struct dma_chan *chan) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| struct rcar_dmac *dmac = to_rcar_dmac(chan->device); |
| struct rcar_dmac_chan_map *map = &rchan->map; |
| struct rcar_dmac_desc_page *page, *_page; |
| struct rcar_dmac_desc *desc; |
| LIST_HEAD(list); |
| |
| /* Protect against ISR */ |
| spin_lock_irq(&rchan->lock); |
| rcar_dmac_chan_halt(rchan); |
| spin_unlock_irq(&rchan->lock); |
| |
| /* |
| * Now no new interrupts will occur, but one might already be |
| * running. Wait for it to finish before freeing resources. |
| */ |
| synchronize_irq(rchan->irq); |
| |
| if (rchan->mid_rid >= 0) { |
| /* The caller is holding dma_list_mutex */ |
| clear_bit(rchan->mid_rid, dmac->modules); |
| rchan->mid_rid = -EINVAL; |
| } |
| |
| list_splice_init(&rchan->desc.free, &list); |
| list_splice_init(&rchan->desc.pending, &list); |
| list_splice_init(&rchan->desc.active, &list); |
| list_splice_init(&rchan->desc.done, &list); |
| list_splice_init(&rchan->desc.wait, &list); |
| |
| rchan->desc.running = NULL; |
| |
| list_for_each_entry(desc, &list, node) |
| rcar_dmac_realloc_hwdesc(rchan, desc, 0); |
| |
| list_for_each_entry_safe(page, _page, &rchan->desc.pages, node) { |
| list_del(&page->node); |
| free_page((unsigned long)page); |
| } |
| |
| /* Remove slave mapping if present. */ |
| if (map->slave.xfer_size) { |
| dma_unmap_resource(chan->device->dev, map->addr, |
| map->slave.xfer_size, map->dir, 0); |
| map->slave.xfer_size = 0; |
| } |
| |
| pm_runtime_put(chan->device->dev); |
| } |
| |
| static struct dma_async_tx_descriptor * |
| rcar_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dma_dest, |
| dma_addr_t dma_src, size_t len, unsigned long flags) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| struct scatterlist sgl; |
| |
| if (!len) |
| return NULL; |
| |
| sg_init_table(&sgl, 1); |
| sg_set_page(&sgl, pfn_to_page(PFN_DOWN(dma_src)), len, |
| offset_in_page(dma_src)); |
| sg_dma_address(&sgl) = dma_src; |
| sg_dma_len(&sgl) = len; |
| |
| return rcar_dmac_chan_prep_sg(rchan, &sgl, 1, dma_dest, |
| DMA_MEM_TO_MEM, flags, false); |
| } |
| |
| static int rcar_dmac_map_slave_addr(struct dma_chan *chan, |
| enum dma_transfer_direction dir) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| struct rcar_dmac_chan_map *map = &rchan->map; |
| phys_addr_t dev_addr; |
| size_t dev_size; |
| enum dma_data_direction dev_dir; |
| |
| if (dir == DMA_DEV_TO_MEM) { |
| dev_addr = rchan->src.slave_addr; |
| dev_size = rchan->src.xfer_size; |
| dev_dir = DMA_TO_DEVICE; |
| } else { |
| dev_addr = rchan->dst.slave_addr; |
| dev_size = rchan->dst.xfer_size; |
| dev_dir = DMA_FROM_DEVICE; |
| } |
| |
| /* Reuse current map if possible. */ |
| if (dev_addr == map->slave.slave_addr && |
| dev_size == map->slave.xfer_size && |
| dev_dir == map->dir) |
| return 0; |
| |
| /* Remove old mapping if present. */ |
| if (map->slave.xfer_size) |
| dma_unmap_resource(chan->device->dev, map->addr, |
| map->slave.xfer_size, map->dir, 0); |
| map->slave.xfer_size = 0; |
| |
| /* Create new slave address map. */ |
| map->addr = dma_map_resource(chan->device->dev, dev_addr, dev_size, |
| dev_dir, 0); |
| |
| if (dma_mapping_error(chan->device->dev, map->addr)) { |
| dev_err(chan->device->dev, |
| "chan%u: failed to map %zx@%pap", rchan->index, |
| dev_size, &dev_addr); |
| return -EIO; |
| } |
| |
| dev_dbg(chan->device->dev, "chan%u: map %zx@%pap to %pad dir: %s\n", |
| rchan->index, dev_size, &dev_addr, &map->addr, |
| dev_dir == DMA_TO_DEVICE ? "DMA_TO_DEVICE" : "DMA_FROM_DEVICE"); |
| |
| map->slave.slave_addr = dev_addr; |
| map->slave.xfer_size = dev_size; |
| map->dir = dev_dir; |
| |
| return 0; |
| } |
| |
| static struct dma_async_tx_descriptor * |
| rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, |
| unsigned int sg_len, enum dma_transfer_direction dir, |
| unsigned long flags, void *context) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| |
| /* Someone calling slave DMA on a generic channel? */ |
| if (rchan->mid_rid < 0 || !sg_len) { |
| dev_warn(chan->device->dev, |
| "%s: bad parameter: len=%d, id=%d\n", |
| __func__, sg_len, rchan->mid_rid); |
| return NULL; |
| } |
| |
| if (rcar_dmac_map_slave_addr(chan, dir)) |
| return NULL; |
| |
| return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, |
| dir, flags, false); |
| } |
| |
| #define RCAR_DMAC_MAX_SG_LEN 32 |
| |
| static struct dma_async_tx_descriptor * |
| rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, |
| size_t buf_len, size_t period_len, |
| enum dma_transfer_direction dir, unsigned long flags) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| struct dma_async_tx_descriptor *desc; |
| struct scatterlist *sgl; |
| unsigned int sg_len; |
| unsigned int i; |
| |
| /* Someone calling slave DMA on a generic channel? */ |
| if (rchan->mid_rid < 0 || buf_len < period_len) { |
| dev_warn(chan->device->dev, |
| "%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n", |
| __func__, buf_len, period_len, rchan->mid_rid); |
| return NULL; |
| } |
| |
| if (rcar_dmac_map_slave_addr(chan, dir)) |
| return NULL; |
| |
| sg_len = buf_len / period_len; |
| if (sg_len > RCAR_DMAC_MAX_SG_LEN) { |
| dev_err(chan->device->dev, |
| "chan%u: sg length %d exceds limit %d", |
| rchan->index, sg_len, RCAR_DMAC_MAX_SG_LEN); |
| return NULL; |
| } |
| |
| /* |
| * Allocate the sg list dynamically as it would consume too much stack |
| * space. |
| */ |
| sgl = kcalloc(sg_len, sizeof(*sgl), GFP_NOWAIT); |
| if (!sgl) |
| return NULL; |
| |
| sg_init_table(sgl, sg_len); |
| |
| for (i = 0; i < sg_len; ++i) { |
| dma_addr_t src = buf_addr + (period_len * i); |
| |
| sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len, |
| offset_in_page(src)); |
| sg_dma_address(&sgl[i]) = src; |
| sg_dma_len(&sgl[i]) = period_len; |
| } |
| |
| desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, |
| dir, flags, true); |
| |
| kfree(sgl); |
| return desc; |
| } |
| |
| static int rcar_dmac_device_config(struct dma_chan *chan, |
| struct dma_slave_config *cfg) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| |
| /* |
| * We could lock this, but you shouldn't be configuring the |
| * channel, while using it... |
| */ |
| rchan->src.slave_addr = cfg->src_addr; |
| rchan->dst.slave_addr = cfg->dst_addr; |
| rchan->src.xfer_size = cfg->src_addr_width; |
| rchan->dst.xfer_size = cfg->dst_addr_width; |
| |
| return 0; |
| } |
| |
| static int rcar_dmac_chan_terminate_all(struct dma_chan *chan) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| unsigned long flags; |
| |
| spin_lock_irqsave(&rchan->lock, flags); |
| rcar_dmac_chan_halt(rchan); |
| spin_unlock_irqrestore(&rchan->lock, flags); |
| |
| /* |
| * FIXME: No new interrupt can occur now, but the IRQ thread might still |
| * be running. |
| */ |
| |
| rcar_dmac_chan_reinit(rchan); |
| |
| return 0; |
| } |
| |
| static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan, |
| dma_cookie_t cookie) |
| { |
| struct rcar_dmac_desc *desc = chan->desc.running; |
| struct rcar_dmac_xfer_chunk *running = NULL; |
| struct rcar_dmac_xfer_chunk *chunk; |
| enum dma_status status; |
| unsigned int residue = 0; |
| unsigned int dptr = 0; |
| unsigned int chcrb; |
| unsigned int tcrb; |
| unsigned int i; |
| |
| if (!desc) |
| return 0; |
| |
| /* |
| * If the cookie corresponds to a descriptor that has been completed |
| * there is no residue. The same check has already been performed by the |
| * caller but without holding the channel lock, so the descriptor could |
| * now be complete. |
| */ |
| status = dma_cookie_status(&chan->chan, cookie, NULL); |
| if (status == DMA_COMPLETE) |
| return 0; |
| |
| /* |
| * If the cookie doesn't correspond to the currently running transfer |
| * then the descriptor hasn't been processed yet, and the residue is |
| * equal to the full descriptor size. |
| * Also, a client driver is possible to call this function before |
| * rcar_dmac_isr_channel_thread() runs. In this case, the "desc.running" |
| * will be the next descriptor, and the done list will appear. So, if |
| * the argument cookie matches the done list's cookie, we can assume |
| * the residue is zero. |
| */ |
| if (cookie != desc->async_tx.cookie) { |
| list_for_each_entry(desc, &chan->desc.done, node) { |
| if (cookie == desc->async_tx.cookie) |
| return 0; |
| } |
| list_for_each_entry(desc, &chan->desc.pending, node) { |
| if (cookie == desc->async_tx.cookie) |
| return desc->size; |
| } |
| list_for_each_entry(desc, &chan->desc.active, node) { |
| if (cookie == desc->async_tx.cookie) |
| return desc->size; |
| } |
| |
| /* |
| * No descriptor found for the cookie, there's thus no residue. |
| * This shouldn't happen if the calling driver passes a correct |
| * cookie value. |
| */ |
| WARN(1, "No descriptor for cookie!"); |
| return 0; |
| } |
| |
| /* |
| * We need to read two registers. |
| * Make sure the control register does not skip to next chunk |
| * while reading the counter. |
| * Trying it 3 times should be enough: Initial read, retry, retry |
| * for the paranoid. |
| */ |
| for (i = 0; i < 3; i++) { |
| chcrb = rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & |
| RCAR_DMACHCRB_DPTR_MASK; |
| tcrb = rcar_dmac_chan_read(chan, RCAR_DMATCRB); |
| /* Still the same? */ |
| if (chcrb == (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & |
| RCAR_DMACHCRB_DPTR_MASK)) |
| break; |
| } |
| WARN_ONCE(i >= 3, "residue might be not continuous!"); |
| |
| /* |
| * In descriptor mode the descriptor running pointer is not maintained |
| * by the interrupt handler, find the running descriptor from the |
| * descriptor pointer field in the CHCRB register. In non-descriptor |
| * mode just use the running descriptor pointer. |
| */ |
| if (desc->hwdescs.use) { |
| dptr = chcrb >> RCAR_DMACHCRB_DPTR_SHIFT; |
| if (dptr == 0) |
| dptr = desc->nchunks; |
| dptr--; |
| WARN_ON(dptr >= desc->nchunks); |
| } else { |
| running = desc->running; |
| } |
| |
| /* Compute the size of all chunks still to be transferred. */ |
| list_for_each_entry_reverse(chunk, &desc->chunks, node) { |
| if (chunk == running || ++dptr == desc->nchunks) |
| break; |
| |
| residue += chunk->size; |
| } |
| |
| /* Add the residue for the current chunk. */ |
| residue += tcrb << desc->xfer_shift; |
| |
| return residue; |
| } |
| |
| static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan, |
| dma_cookie_t cookie, |
| struct dma_tx_state *txstate) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| enum dma_status status; |
| unsigned long flags; |
| unsigned int residue; |
| |
| status = dma_cookie_status(chan, cookie, txstate); |
| if (status == DMA_COMPLETE || !txstate) |
| return status; |
| |
| spin_lock_irqsave(&rchan->lock, flags); |
| residue = rcar_dmac_chan_get_residue(rchan, cookie); |
| spin_unlock_irqrestore(&rchan->lock, flags); |
| |
| /* if there's no residue, the cookie is complete */ |
| if (!residue) |
| return DMA_COMPLETE; |
| |
| dma_set_residue(txstate, residue); |
| |
| return status; |
| } |
| |
| static void rcar_dmac_issue_pending(struct dma_chan *chan) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| unsigned long flags; |
| |
| spin_lock_irqsave(&rchan->lock, flags); |
| |
| if (list_empty(&rchan->desc.pending)) |
| goto done; |
| |
| /* Append the pending list to the active list. */ |
| list_splice_tail_init(&rchan->desc.pending, &rchan->desc.active); |
| |
| /* |
| * If no transfer is running pick the first descriptor from the active |
| * list and start the transfer. |
| */ |
| if (!rchan->desc.running) { |
| struct rcar_dmac_desc *desc; |
| |
| desc = list_first_entry(&rchan->desc.active, |
| struct rcar_dmac_desc, node); |
| rchan->desc.running = desc; |
| |
| rcar_dmac_chan_start_xfer(rchan); |
| } |
| |
| done: |
| spin_unlock_irqrestore(&rchan->lock, flags); |
| } |
| |
| static void rcar_dmac_device_synchronize(struct dma_chan *chan) |
| { |
| struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); |
| |
| synchronize_irq(rchan->irq); |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * IRQ handling |
| */ |
| |
| static irqreturn_t rcar_dmac_isr_desc_stage_end(struct rcar_dmac_chan *chan) |
| { |
| struct rcar_dmac_desc *desc = chan->desc.running; |
| unsigned int stage; |
| |
| if (WARN_ON(!desc || !desc->cyclic)) { |
| /* |
| * This should never happen, there should always be a running |
| * cyclic descriptor when a descriptor stage end interrupt is |
| * triggered. Warn and return. |
| */ |
| return IRQ_NONE; |
| } |
| |
| /* Program the interrupt pointer to the next stage. */ |
| stage = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & |
| RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT; |
| rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(stage)); |
| |
| return IRQ_WAKE_THREAD; |
| } |
| |
| static irqreturn_t rcar_dmac_isr_transfer_end(struct rcar_dmac_chan *chan) |
| { |
| struct rcar_dmac_desc *desc = chan->desc.running; |
| irqreturn_t ret = IRQ_WAKE_THREAD; |
| |
| if (WARN_ON_ONCE(!desc)) { |
| /* |
| * This should never happen, there should always be a running |
| * descriptor when a transfer end interrupt is triggered. Warn |
| * and return. |
| */ |
| return IRQ_NONE; |
| } |
| |
| /* |
| * The transfer end interrupt isn't generated for each chunk when using |
| * descriptor mode. Only update the running chunk pointer in |
| * non-descriptor mode. |
| */ |
| if (!desc->hwdescs.use) { |
| /* |
| * If we haven't completed the last transfer chunk simply move |
| * to the next one. Only wake the IRQ thread if the transfer is |
| * cyclic. |
| */ |
| if (!list_is_last(&desc->running->node, &desc->chunks)) { |
| desc->running = list_next_entry(desc->running, node); |
| if (!desc->cyclic) |
| ret = IRQ_HANDLED; |
| goto done; |
| } |
| |
| /* |
| * We've completed the last transfer chunk. If the transfer is |
| * cyclic, move back to the first one. |
| */ |
| if (desc->cyclic) { |
| desc->running = |
| list_first_entry(&desc->chunks, |
| struct rcar_dmac_xfer_chunk, |
| node); |
| goto done; |
| } |
| } |
| |
| /* The descriptor is complete, move it to the done list. */ |
| list_move_tail(&desc->node, &chan->desc.done); |
| |
| /* Queue the next descriptor, if any. */ |
| if (!list_empty(&chan->desc.active)) |
| chan->desc.running = list_first_entry(&chan->desc.active, |
| struct rcar_dmac_desc, |
| node); |
| else |
| chan->desc.running = NULL; |
| |
| done: |
| if (chan->desc.running) |
| rcar_dmac_chan_start_xfer(chan); |
| |
| return ret; |
| } |
| |
| static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev) |
| { |
| u32 mask = RCAR_DMACHCR_DSE | RCAR_DMACHCR_TE; |
| struct rcar_dmac_chan *chan = dev; |
| irqreturn_t ret = IRQ_NONE; |
| bool reinit = false; |
| u32 chcr; |
| |
| spin_lock(&chan->lock); |
| |
| chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); |
| if (chcr & RCAR_DMACHCR_CAE) { |
| struct rcar_dmac *dmac = to_rcar_dmac(chan->chan.device); |
| |
| /* |
| * We don't need to call rcar_dmac_chan_halt() |
| * because channel is already stopped in error case. |
| * We need to clear register and check DE bit as recovery. |
| */ |
| rcar_dmac_write(dmac, RCAR_DMACHCLR, 1 << chan->index); |
| rcar_dmac_chcr_de_barrier(chan); |
| reinit = true; |
| goto spin_lock_end; |
| } |
| |
| if (chcr & RCAR_DMACHCR_TE) |
| mask |= RCAR_DMACHCR_DE; |
| rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask); |
| if (mask & RCAR_DMACHCR_DE) |
| rcar_dmac_chcr_de_barrier(chan); |
| |
| if (chcr & RCAR_DMACHCR_DSE) |
| ret |= rcar_dmac_isr_desc_stage_end(chan); |
| |
| if (chcr & RCAR_DMACHCR_TE) |
| ret |= rcar_dmac_isr_transfer_end(chan); |
| |
| spin_lock_end: |
| spin_unlock(&chan->lock); |
| |
| if (reinit) { |
| dev_err(chan->chan.device->dev, "Channel Address Error\n"); |
| |
| rcar_dmac_chan_reinit(chan); |
| ret = IRQ_HANDLED; |
| } |
| |
| return ret; |
| } |
| |
| static irqreturn_t rcar_dmac_isr_channel_thread(int irq, void *dev) |
| { |
| struct rcar_dmac_chan *chan = dev; |
| struct rcar_dmac_desc *desc; |
| struct dmaengine_desc_callback cb; |
| |
| spin_lock_irq(&chan->lock); |
| |
| /* For cyclic transfers notify the user after every chunk. */ |
| if (chan->desc.running && chan->desc.running->cyclic) { |
| desc = chan->desc.running; |
| dmaengine_desc_get_callback(&desc->async_tx, &cb); |
| |
| if (dmaengine_desc_callback_valid(&cb)) { |
| spin_unlock_irq(&chan->lock); |
| dmaengine_desc_callback_invoke(&cb, NULL); |
| spin_lock_irq(&chan->lock); |
| } |
| } |
| |
| /* |
| * Call the callback function for all descriptors on the done list and |
| * move them to the ack wait list. |
| */ |
| while (!list_empty(&chan->desc.done)) { |
| desc = list_first_entry(&chan->desc.done, struct rcar_dmac_desc, |
| node); |
| dma_cookie_complete(&desc->async_tx); |
| list_del(&desc->node); |
| |
| dmaengine_desc_get_callback(&desc->async_tx, &cb); |
| if (dmaengine_desc_callback_valid(&cb)) { |
| spin_unlock_irq(&chan->lock); |
| /* |
| * We own the only reference to this descriptor, we can |
| * safely dereference it without holding the channel |
| * lock. |
| */ |
| dmaengine_desc_callback_invoke(&cb, NULL); |
| spin_lock_irq(&chan->lock); |
| } |
| |
| list_add_tail(&desc->node, &chan->desc.wait); |
| } |
| |
| spin_unlock_irq(&chan->lock); |
| |
| /* Recycle all acked descriptors. */ |
| rcar_dmac_desc_recycle_acked(chan); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * OF xlate and channel filter |
| */ |
| |
| static bool rcar_dmac_chan_filter(struct dma_chan *chan, void *arg) |
| { |
| struct rcar_dmac *dmac = to_rcar_dmac(chan->device); |
| struct of_phandle_args *dma_spec = arg; |
| |
| /* |
| * FIXME: Using a filter on OF platforms is a nonsense. The OF xlate |
| * function knows from which device it wants to allocate a channel from, |
| * and would be perfectly capable of selecting the channel it wants. |
| * Forcing it to call dma_request_channel() and iterate through all |
| * channels from all controllers is just pointless. |
| */ |
| if (chan->device->device_config != rcar_dmac_device_config || |
| dma_spec->np != chan->device->dev->of_node) |
| return false; |
| |
| return !test_and_set_bit(dma_spec->args[0], dmac->modules); |
| } |
| |
| static struct dma_chan *rcar_dmac_of_xlate(struct of_phandle_args *dma_spec, |
| struct of_dma *ofdma) |
| { |
| struct rcar_dmac_chan *rchan; |
| struct dma_chan *chan; |
| dma_cap_mask_t mask; |
| |
| if (dma_spec->args_count != 1) |
| return NULL; |
| |
| /* Only slave DMA channels can be allocated via DT */ |
| dma_cap_zero(mask); |
| dma_cap_set(DMA_SLAVE, mask); |
| |
| chan = dma_request_channel(mask, rcar_dmac_chan_filter, dma_spec); |
| if (!chan) |
| return NULL; |
| |
| rchan = to_rcar_dmac_chan(chan); |
| rchan->mid_rid = dma_spec->args[0]; |
| |
| return chan; |
| } |
| |
| /* ----------------------------------------------------------------------------- |
| * Power management |
| */ |
| |
| #ifdef CONFIG_PM |
| static int rcar_dmac_runtime_suspend(struct device *dev) |
| { |
| return 0; |
| } |
| |
| static int rcar_dmac_runtime_resume(struct device *dev) |
| { |
| struct rcar_dmac *dmac = dev_get_drvdata(dev); |
| |
| return rcar_dmac_init(dmac); |
| } |
| #endif |
| |
| static const struct dev_pm_ops rcar_dmac_pm = { |
| /* |
| * TODO for system sleep/resume: |
| * - Wait for the current transfer to complete and stop the device, |
| * - Resume transfers, if any. |
| */ |
| SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, |
| pm_runtime_force_resume) |
| SET_RUNTIME_PM_OPS(rcar_dmac_runtime_suspend, rcar_dmac_runtime_resume, |
| NULL) |
| }; |
| |
| /* ----------------------------------------------------------------------------- |
| * Probe and remove |
| */ |
| |
| static int rcar_dmac_chan_probe(struct rcar_dmac *dmac, |
| struct rcar_dmac_chan *rchan, |
| unsigned int index) |
| { |
| struct platform_device *pdev = to_platform_device(dmac->dev); |
| struct dma_chan *chan = &rchan->chan; |
| char pdev_irqname[5]; |
| char *irqname; |
| int ret; |
| |
| rchan->index = index; |
| rchan->iomem = dmac->iomem + RCAR_DMAC_CHAN_OFFSET(index); |
| rchan->mid_rid = -EINVAL; |
| |
| spin_lock_init(&rchan->lock); |
| |
| INIT_LIST_HEAD(&rchan->desc.free); |
| INIT_LIST_HEAD(&rchan->desc.pending); |
| INIT_LIST_HEAD(&rchan->desc.active); |
| INIT_LIST_HEAD(&rchan->desc.done); |
| INIT_LIST_HEAD(&rchan->desc.wait); |
| |
| /* Request the channel interrupt. */ |
| sprintf(pdev_irqname, "ch%u", index); |
| rchan->irq = platform_get_irq_byname(pdev, pdev_irqname); |
| if (rchan->irq < 0) { |
| dev_err(dmac->dev, "no IRQ specified for channel %u\n", index); |
| return -ENODEV; |
| } |
| |
| irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u", |
| dev_name(dmac->dev), index); |
| if (!irqname) |
| return -ENOMEM; |
| |
| /* |
| * Initialize the DMA engine channel and add it to the DMA engine |
| * channels list. |
| */ |
| chan->device = &dmac->engine; |
| dma_cookie_init(chan); |
| |
| list_add_tail(&chan->device_node, &dmac->engine.channels); |
| |
| ret = devm_request_threaded_irq(dmac->dev, rchan->irq, |
| rcar_dmac_isr_channel, |
| rcar_dmac_isr_channel_thread, 0, |
| irqname, rchan); |
| if (ret) { |
| dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", |
| rchan->irq, ret); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac) |
| { |
| struct device_node *np = dev->of_node; |
| int ret; |
| |
| ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels); |
| if (ret < 0) { |
| dev_err(dev, "unable to read dma-channels property\n"); |
| return ret; |
| } |
| |
| if (dmac->n_channels <= 0 || dmac->n_channels >= 100) { |
| dev_err(dev, "invalid number of channels %u\n", |
| dmac->n_channels); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int rcar_dmac_probe(struct platform_device *pdev) |
| { |
| const enum dma_slave_buswidth widths = DMA_SLAVE_BUSWIDTH_1_BYTE | |
| DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES | |
| DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES | |
| DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES; |
| unsigned int channels_offset = 0; |
| struct dma_device *engine; |
| struct rcar_dmac *dmac; |
| struct resource *mem; |
| unsigned int i; |
| int ret; |
| |
| dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); |
| if (!dmac) |
| return -ENOMEM; |
| |
| dmac->dev = &pdev->dev; |
| platform_set_drvdata(pdev, dmac); |
| dma_set_mask_and_coherent(dmac->dev, DMA_BIT_MASK(40)); |
| |
| ret = rcar_dmac_parse_of(&pdev->dev, dmac); |
| if (ret < 0) |
| return ret; |
| |
| /* |
| * A still unconfirmed hardware bug prevents the IPMMU microTLB 0 to be |
| * flushed correctly, resulting in memory corruption. DMAC 0 channel 0 |
| * is connected to microTLB 0 on currently supported platforms, so we |
| * can't use it with the IPMMU. As the IOMMU API operates at the device |
| * level we can't disable it selectively, so ignore channel 0 for now if |
| * the device is part of an IOMMU group. |
| */ |
| if (pdev->dev.iommu_group) { |
| dmac->n_channels--; |
| channels_offset = 1; |
| } |
| |
| dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, |
| sizeof(*dmac->channels), GFP_KERNEL); |
| if (!dmac->channels) |
| return -ENOMEM; |
| |
| /* Request resources. */ |
| mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| dmac->iomem = devm_ioremap_resource(&pdev->dev, mem); |
| if (IS_ERR(dmac->iomem)) |
| return PTR_ERR(dmac->iomem); |
| |
| /* Enable runtime PM and initialize the device. */ |
| pm_runtime_enable(&pdev->dev); |
| ret = pm_runtime_get_sync(&pdev->dev); |
| if (ret < 0) { |
| dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret); |
| return ret; |
| } |
| |
| ret = rcar_dmac_init(dmac); |
| pm_runtime_put(&pdev->dev); |
| |
| if (ret) { |
| dev_err(&pdev->dev, "failed to reset device\n"); |
| goto error; |
| } |
| |
| /* Initialize engine */ |
| engine = &dmac->engine; |
| |
| dma_cap_set(DMA_MEMCPY, engine->cap_mask); |
| dma_cap_set(DMA_SLAVE, engine->cap_mask); |
| |
| engine->dev = &pdev->dev; |
| engine->copy_align = ilog2(RCAR_DMAC_MEMCPY_XFER_SIZE); |
| |
| engine->src_addr_widths = widths; |
| engine->dst_addr_widths = widths; |
| engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); |
| engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; |
| |
| engine->device_alloc_chan_resources = rcar_dmac_alloc_chan_resources; |
| engine->device_free_chan_resources = rcar_dmac_free_chan_resources; |
| engine->device_prep_dma_memcpy = rcar_dmac_prep_dma_memcpy; |
| engine->device_prep_slave_sg = rcar_dmac_prep_slave_sg; |
| engine->device_prep_dma_cyclic = rcar_dmac_prep_dma_cyclic; |
| engine->device_config = rcar_dmac_device_config; |
| engine->device_pause = rcar_dmac_chan_pause; |
| engine->device_terminate_all = rcar_dmac_chan_terminate_all; |
| engine->device_tx_status = rcar_dmac_tx_status; |
| engine->device_issue_pending = rcar_dmac_issue_pending; |
| engine->device_synchronize = rcar_dmac_device_synchronize; |
| |
| INIT_LIST_HEAD(&engine->channels); |
| |
| for (i = 0; i < dmac->n_channels; ++i) { |
| ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], |
| i + channels_offset); |
| if (ret < 0) |
| goto error; |
| } |
| |
| /* Register the DMAC as a DMA provider for DT. */ |
| ret = of_dma_controller_register(pdev->dev.of_node, rcar_dmac_of_xlate, |
| NULL); |
| if (ret < 0) |
| goto error; |
| |
| /* |
| * Register the DMA engine device. |
| * |
| * Default transfer size of 32 bytes requires 32-byte alignment. |
| */ |
| ret = dma_async_device_register(engine); |
| if (ret < 0) |
| goto error; |
| |
| return 0; |
| |
| error: |
| of_dma_controller_free(pdev->dev.of_node); |
| pm_runtime_disable(&pdev->dev); |
| return ret; |
| } |
| |
| static int rcar_dmac_remove(struct platform_device *pdev) |
| { |
| struct rcar_dmac *dmac = platform_get_drvdata(pdev); |
| |
| of_dma_controller_free(pdev->dev.of_node); |
| dma_async_device_unregister(&dmac->engine); |
| |
| pm_runtime_disable(&pdev->dev); |
| |
| return 0; |
| } |
| |
| static void rcar_dmac_shutdown(struct platform_device *pdev) |
| { |
| struct rcar_dmac *dmac = platform_get_drvdata(pdev); |
| |
| rcar_dmac_stop_all_chan(dmac); |
| } |
| |
| static const struct of_device_id rcar_dmac_of_ids[] = { |
| { .compatible = "renesas,rcar-dmac", }, |
| { /* Sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, rcar_dmac_of_ids); |
| |
| static struct platform_driver rcar_dmac_driver = { |
| .driver = { |
| .pm = &rcar_dmac_pm, |
| .name = "rcar-dmac", |
| .of_match_table = rcar_dmac_of_ids, |
| }, |
| .probe = rcar_dmac_probe, |
| .remove = rcar_dmac_remove, |
| .shutdown = rcar_dmac_shutdown, |
| }; |
| |
| module_platform_driver(rcar_dmac_driver); |
| |
| MODULE_DESCRIPTION("R-Car Gen2 DMA Controller Driver"); |
| MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); |
| MODULE_LICENSE("GPL v2"); |